Assalamuilaikum. In fatwa No. 177059, you said that if a person makes a general repentance for all the kufr/shirk acts that he has committed, even though he forgets some, it would be enough to get his sins forgiven by allah but what if he didn't know that some acts that he committed is kufr/shirk, would he still be forgiven even though he did not know that it was kufr/shirk?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

If a person commits an act of Kufr (unbelief) or Shirk (idolatry) and does not know that it is Kufr or Shirk, then he might be excused in principle in the sight of Allaah, so Allaah does not hold him accountable for this act and he is not considered as an unbeliever or idolater because if a person is unable to gain knowledge, he is excused due to his ignorance; Allaah says (what means): {And Allaah would not let a people stray after He has guided them until He makes clear to them what they should avoid. Indeed, Allaah is Knowing of all things.} [Quran 9:115]

If we assumed that he was in a situation in which he was not excused for his ignorance, like if he was able to gain knowledge but did not seek it, then if he makes a general repentance, such an act of Kufr or Shirk would be covered by it. This is indeed a Favor and Mercy from Allaah but many people do not know it, and if they knew it, most of them are not grateful.

For more benefit on the conditions of judging a person as an unbeliever, please refer to Fataawa 8106 and 87963.

Allaah Knows best.